To perform an endoscopy procedure, it is often necessary to create a hollow space inside the body. For this purpose, a gas, for example air or CO2, is usually conveyed from a proximal end area of an endoscope (area near the user) through a line extending inside the shank of the endoscope to the distal end of the endoscope (end remote from the user). It emerges there at a suitable pressure and, in the area of the distal end of the endoscope, creates a hollow space within which the procedure can be performed with endoscopic monitoring. Since the distal window of the endoscopic lens system can become soiled during the procedure, as a result of which the view is impaired, an irrigation liquid can be conveyed through the shank of the endoscope to the distal end of the endoscope in order to use this liquid to clean the distal window during the endoscopy procedure. Moreover, a suction system can be provided, with which the irrigation liquid and, if appropriate, any detached pieces of tissue can be aspirated from the operating site.
To control the insufflation and irrigation in known endoscopes, a manually operable insufflation and irrigation valve is arranged on the handle of the endoscope. A proximal portion of an insufflation line is attached to a valve housing of the known insufflation and irrigation valve, via which proximal portion an insufflator can be connected to the endoscope so as to make available the insufflation gas at the required pressure. Moreover, a proximal portion of an irrigation line is attached to the valve housing, in which line an irrigation liquid from a storage container is likewise made available at a suitable pressure. A distal portion of the insufflation line and a distal portion of the irrigation line, through which the insufflation gas and the irrigation liquid can be conveyed to the distal end of the endoscope, are also attached to the valve housing. The insufflation and irrigation valve comprises a plunger which is arranged movably in the valve housing and which can be actuated by a valve button, wherein the proximal portion and the distal portion of the irrigation line can be connected to each other or separated from each other by movement of the plunger. The valve button and the plunger each have a bore which at one end is connected to the proximal portion of the insufflation line and at the other end terminates in an opening through which the insufflation gas can escape to the environment. When the opening is closed with a finger by the user, pressure is able to build up in the insufflation line and insufflation can take place. When the insufflation and irrigation valve is pressed in by further pressure from the finger, the distal portion is connected to the proximal portion of the irrigation line, such that irrigation liquid can flow to the distal end of the endoscope.
In the non-actuated state of the valve, i.e. when neither irrigation nor insufflation is intended to take place, the insufflation gas made available by the insufflator escapes to the environment through the opening. Particularly if CO2 is used as insufflation gas, this entails considerable costs, since the storage container, for example a bottle of CO2, is unnecessarily emptied and has to be replaced early on.
EP 1 707 107 A1 discloses an insufflation and irrigation valve which has a cylinder element with an approximately cylindrical bore in which a cylindrical outer plunger is arranged to be movable. A distal portion of an air line is connected to the bottom of the bore, and a proximal portion of the air line and a proximal and a distal portion of a water line are attached at predetermined positions to the side of the cylinder element. An inner plunger is arranged movably in a bore of the outer plunger and, in its interior, has an air channel formed by transverse bores and a longitudinal bore. A base plate is arranged on the underside of the outer plunger, on which base plate a spring is supported that pretensions the inner plunger. The air channel communicates with a hole in the base plate and, when the inner plunger is pressed manually into the outer plunger counter to the force of the spring, communicates with an aperture and a peripheral groove of the outer plunger. In a first position of the outer plunger, the peripheral groove of the outer plunger communicates with the distal portion of the air line, such that, by actuation of the inner plunger, a connection can be produced between the proximal portion and the distal portion of the air line. In a second position of the outer plunger, a connection is produced, via a peripheral groove of the outer plunger, between the proximal portion and the distal portion of the water line.
Since the valve may become soiled during the operation of the insufflation and irrigation valve and, in particular, contamination with bodily fluid cannot be completely ruled out, cleaning and sterilization are necessary in the case of a reusable valve. However, in the described insufflation and irrigation valve, this is possible only to a limited extent. Dismantling is difficult in particular, and it is barely possible to clean the channels formed in the inner plunger. Moreover, the base plate on which the spring bears prevents the central bore of the outer plunger from being cleaned with a brush guided through said bore.